well atm I am using GH 3 part and it is the only thing I have used since day 1 and got no gripes here. Since after a year or so of growing now and I still dont have a PH meter i recently found some combo meters on E-Bay that will do temp (C or F), EC or PPM and also PH for under $100 and it is a continous read (sensor goes into tub and reads constantly). Only thing I have been doing my PH with is an aquarium kit and to tell you the truth I have got to be real lucky to get the yields that we have been getting but I have only been running like 5 or 6 plants in a E&F setup. Maybe we all can compare notes on strain, PH level used, brand of nutes, and type of system. I think it would be quite informative to know that growing Northern Lights in an E&F setup best grows at PH 5.7 with GH 3part but in DWC you would see better results at 5.1 ....... just a thought but for right now it's time to grab a bite to eat and sit back and relax